qgstextrendererutils.h

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/***************************************************************************
  qgstextrendererutils.h
  -----------------
   begin                : May 2020
   copyright            : (C) Nyall Dawson
   email                : nyall dot dawson at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSTEXTRENDERERUTILS_H
#define QGSTEXTRENDERERUTILS_H
 
#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgstextbackgroundsettings.h"
#include "qgstextmetrics.h"
#include "qgstextshadowsettings.h"

class CORE_EXPORT QgsTextRendererUtils
{
  public:
    static QgsTextBackgroundSettings::ShapeType decodeShapeType( const QString &string );

    static QgsTextBackgroundSettings::SizeType decodeBackgroundSizeType( const QString &string );

    static QgsTextBackgroundSettings::RotationType decodeBackgroundRotationType( const QString &string );

    static QgsTextShadowSettings::ShadowPlacement decodeShadowPlacementType( const QString &string );

    static QString encodeTextOrientation( Qgis::TextOrientation orientation );

    static Qgis::TextOrientation decodeTextOrientation( const QString &name, bool *ok = nullptr );

    static Qgis::RenderUnit convertFromOldLabelUnit( int val ) SIP_SKIP;

    static QColor readColor( QgsVectorLayer *layer, const QString &property, const QColor &defaultColor = Qt::black, bool withAlpha = true ) SIP_SKIP;
 
#ifndef SIP_RUN

    class CurvedGraphemePlacement
    {
      public:
        double x = 0;
        double y = 0;
        double width = 0;
        double height = 0;
        double angle = 0;
        int graphemeIndex = 0;
        bool isWhitespace = false;
    };

    class CurvePlacementProperties
    {
      public:
        QVector< QgsTextRendererUtils::CurvedGraphemePlacement > graphemePlacement;
        int upsideDownCharCount = 0;
        bool labeledLineSegmentIsRightToLeft = false;
        bool flippedCharacterPlacementToGetUprightLabels = false;
    };

    enum LabelLineDirection
    {
      RespectPainterOrientation, 
      FollowLineDirection        
    };

    static std::unique_ptr< CurvePlacementProperties > generateCurvedTextPlacement(
      const QgsPrecalculatedTextMetrics &metrics,
      const QPolygonF &line,
      double offsetAlongLine,
      LabelLineDirection direction = RespectPainterOrientation,
      double maxConcaveAngle = -1,
      double maxConvexAngle = -1,
      Qgis::CurvedTextFlags flags = Qgis::CurvedTextFlags(),
      Qgis::TextAnchorPoint textAnchor = Qgis::TextAnchorPoint::StartOfText
    ) SIP_SKIP;

    static std::unique_ptr< CurvePlacementProperties > generateCurvedTextPlacement(
      const QgsPrecalculatedTextMetrics &metrics,
      const double *x,
      const double *y,
      int numPoints,
      const std::vector< double> &pathDistances,
      double offsetAlongLine,
      LabelLineDirection direction = RespectPainterOrientation,
      double maxConcaveAngle = -1,
      double maxConvexAngle = -1,
      Qgis::CurvedTextFlags flags = Qgis::CurvedTextFlags(),
      double additionalCharacterSpacing = 0.0,
      double additionalWordSpacing = 0.0,
      Qgis::TextAnchorPoint textAnchor = Qgis::TextAnchorPoint::StartOfText
    ) SIP_SKIP;
#endif
 
  private:
    static std::unique_ptr< CurvePlacementProperties > generateCurvedTextPlacementPrivate(
      const QgsPrecalculatedTextMetrics &metrics,
      const double *x,
      const double *y,
      int numPoints,
      const std::vector< double> &pathDistances,
      double offsetAlongLine,
      LabelLineDirection direction,
      Qgis::CurvedTextFlags flags,
      double maxConcaveAngle = -1,
      double maxConvexAngle = -1,
      bool isSecondAttempt = false,
      double additionalCharacterSpacing = 0,
      double additionalWordSpacing = 0,
      Qgis::TextAnchorPoint textAnchor = Qgis::TextAnchorPoint::StartOfText
    ) SIP_SKIP;

    static bool nextCharPosition(
      double charWidth,
      const std::vector< double > &pathDistances,
      const double *x,
      const double *y,
      int numPoints,
      int &index,
      double &currentDistanceAlongSegment,
      double &characterStartX,
      double &characterStartY,
      double &characterEndX,
      double &characterEndY,
      Qgis::CurvedTextFlags flags,
      double additionalSpacing
    );
 
    static void findLineCircleIntersection( double cx, double cy, double radius, double x1, double y1, double x2, double y2, double &xRes, double &yRes );
};
 
 
#endif // QGSTEXTRENDERERUTILS_H